Safety mechanisms for firearms intended to prevent unintentional or inadvertent percussion are well-known. These safety mechanisms are of two types.
For firearms provided with a hammer, the safety device blocks the hammer in the cocked position ready to shoot, which nevertheless still involves risks if the weapon is dropped. In such a case, the system has the disadvantage of causing damage to the hammer and sear mechanisms or of causing the accidental firing of a bullet.
As far as hammerless firearms are concerned, these are generally not provided with manual safety, which induces a risk of unwanted shooting. In this type of weapon, the firing pin is hooked by a mechanism which, when the trigger is pressed, releases the firing pin from its cocked position and thus allows percussion. In other cases, the firing pin is in an intermediate position between the percussion position and the armed position. The stroke for fully cocking the firing pin is effected when the trigger is pressed thanks to the trigger bar. At the end of the stroke, the trigger bar is retracted and releases the firing pin. The latter, actuated by its spring, can then, by its forward movement, strike the primer of the cartridge located in the chamber. This system generally does not have manual safety mechanism and therefore also involves a risk of inadvertent firing.